|I have a 10-yr. old clump of the grass Miscanthus sinensis gracillimus. It gets a fair amount of sun. It blooms very late, pushing up plumes about Nov. 1. This means most years the growth is cut short by frost weeks before the plumes appear. A doctor's office a few miles from my home has several clumps of this grass that produce magnificent plumes well before frost. Why is this?|
|There a few things that I can imagine are creating a problem for your miscanthus. First, perhaps it is in a colder mini-climate zone , delaying the bloom until later than others in your neighborhood.
Second, and perhaps more to the point, may bethat it is lacking phosphorus. A phosphorus shortage can slow root growth as well as flowering.
Phosphorus is the second number in the series of three on the bags of fertilizers you can buy. ie. 5-10-15 (The 10 in this series is the phosphorus.) I would suggest feeding it a bit of this even though grasses as usual don't need much supplemental fertilizer. You can administer this fertilizer right now. By spring it will have worked itself down to the roots where it's put to use immediately!